Abstract

Off Chennai. the trawlers engaged in night fishing realised nearly 25% higher catch rate (42.4 kglh) than those engaged in
day fishing (34.3 kglh) during 1996-1998. Barring June and July, the catch rate of night trawlers was higher for 10
months in a year. The day : night ratio of catch rate was very high for catfishes, rays, eels and flatfishes. On the other
hand, the ratio was low for carangids, perches and squids. The die1 and seasonal vertical migration of fishes and the
possibility of utilizing this information for fishing are discussed.